379
FXUS65 KBYZ 211505
AFDBYZ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BILLINGS MT
905 AM MDT TUE JUL 21 2026
KEY MESSAGES
- CHANCE OF THUNDERSTORMS RETURNS TO MAINLY MOUNTAINS TODAY, THEN
MOST OF AREA WEDNESDAY & THURSDAY. STORMS COULD PRODUCE VERY
HEAVY RAINFALL AND GUSTY WINDS.
- THUNDERSTORMS HAVE THE POTENTIAL TO CREATE VERY HEAVY RAINFALL
OVER BURN SCARS WEDNESDAY EVENING. PLAN AHEAD IF RECREATING NEAR
ANY BURN SCARS.
- THIS WEEKEND IS LOOKING HOTTER & DRIER; A RETURN OF TRIPLE DIGIT
HEAT EXPECTED. FIRE DANGER MAY INCREASE.
UPDATE
HAVE ISSUED A FLOOD WATCH FOR POTENTIAL FLASH FLOODING WEDNESDAY
AFTERNOON AND EVENING, MAINLY FOR AREAS ALONG THE MOUNTAINS AND
FOOTHILLS. THIS INCLUDES THE EAST SIDE, ROBERTSON DRAW AND ELK
BURN SCARS.
FOR TODAY. ISOLATED LIGHT SHOWERS HAVE DEVELOPED OVER OUR NORTH
AND EAST EARLY THIS MORNING. THIS ACTIVITY IS TIED TO VERY
ELEVATED MOISTURE/INSTABILITY (IN THE 550-500MB LAYER) AND IS
MOSTLY THICK AC, BUT MILES CITY RECENTLY REPORTED LIGHT RAIN OUT
OF THESE MID CLOUDS. HAVE ADJUSTED MORNING POPS FOR A MENTION OF
ISOLATED SHOWERS. OTHERWISE, RISK OF WET T-STORMS FAVORS OUR SOUTH
IN THE LATE AFTERNOON AND EVENING. MESOANALYSIS ALREADY SHOWS
PWATS UP TO 1+ INCHES, SO STORMS WILL PRODUCE HEAVY RAIN. LOOK FOR
HIGH TEMPS IN THE 80S TO NEAR 90F. JKL
DISCUSSION
TODAY THROUGH MONDAY...
A PERSISTENT RIDGE OVER THE WESTERN US WILL CONTINUE TO BRING
WARM TEMPERATURES AS WELL AS PULL ATMOSPHERIC MOISTURE FROM THE
SOUTHWEST US. CLOUD COVER AND PRECIPITATION OVER THE NEXT FEW DAYS
WILL KEEP TEMPERATURES AROUND NORMAL, IN THE 80S TO LOW 90S. AN
INCREASE IN ATMOSPHERIC MOISTURE THROUGH THURSDAY ALONG WITH
MODEL SOUNDINGS INDICATE SLOW MOVING STORMS WILL INCREASE THE
POTENTIAL FOR HEAVY RAIN. A 10-20% CHANCE OF SHOWERS EXISTS ACROSS
THE AREA TODAY WITH MODERATE CHANCES FOR THE HIGHER TERRAIN
ACROSS SOUTHERN MT AND NORTHERN WY. SHORT TERM ENSEMBLES GENERALLY
HAVE THE HIGHEST PRECIPITATION AMOUNTS OVER THE ABSAROKA
BEARTOOTHS TODAY (MAINLY FOR THIS EVENING). THE POTENTIAL FOR
HEAVY RAIN BECOMES MORE WIDESPREAD BY WEDNESDAY, SPREADING ACROSS
SOUTHERN MT AND NORTHERN WY. MODERATE TO HIGH CHANCES FOR AT LEAST
A HALF AN INCH IN AN HOUR EXIST FOR THE MOUNTAINS AND FOOTHILLS
WEDNESDAY EVENING. THOSE RECREATING NEAR ANY BURN SCARS SUCH AS
THE ROBERTSON DRAW, EAST SIDE OR ELK SHOULD USE CAUTION DURING
THESE TIMES AND STAY AWARE OF CHANGING CONDITIONS. AS FAR AS
THUNDERSTORMS GO, THEY LOOK TO REMAIN WEAK AND CONFINED TO THE
MOUNTAINS AND FOOTHILLS THE NEXT COUPLE DAYS. LATE WEDNESDAY INTO
THURSDAY, INSTABILITY IS EXPECTED TO SPREAD ONTO THE PLAINS,
INCREASING THUNDERSTORM AND HEAVY RAINFALL POTENTIAL.
FRIDAY AND SATURDAY, ELEVATED ATMOSPHERIC MOISTURE WILL RETREAT
SOUTH AND MID LEVEL HEIGHTS WILL BUILD, ALLOWING FOR HOT
TEMPERATURES IN THE UPPER 90S AND LOW 100S TO RETURN. LOW CHANCES
FOR AN AFTERNOON SHOWER AND THUNDERSTORMS REMAIN IN THE FORECAST
FOR THESE DAYS. ENSEMBLES HINT AT SOME ENERGY MOVING ACROSS
NORTHERN MT OVER THE WEEKEND WHICH WOULD INCREASE THE POTENTIAL
FOR BREEZY CONDITIONS. WITH THE INCREASING HOT, DRY AND
POTENTIALLY BREEZY CONDITIONS, FIRE WEATHER CONCERNS COULD ARISE
FOR THOSE WHO HAVE NOT RECEIVED RECENT PRECIPITATION. THIS WILL BE
SOMETHING TO WATCH. TEMPERATURES IN THE 90S TO 100 PERSIST SUNDAY
AND MONDAY. TS
AVIATION
AN ISOLATED SHOWER OR VIRGA IS POSSIBLE ACROSS PORTIONS OF
MONTANA THIS MORNING, HIGHEST CHANCE (20%) ACROSS EAST CENTRAL
MONTANA. WILDFIRE SMOKE FROM THE PACIFIC NW MAY PRODUCE SLANT
RANGE VISIBILITY REDUCTIONS AT TIMES, BUT SURFACE VISIBILITY
REDUCTIONS ARE NOT EXPECTED. THE CHANCE OF SHOWERS AND
THUNDERSTORMS INCREASE OVER THE MOUNTAINS THIS AFTERNOON AND
EVENING. BT/ARCHER
PRELIMINARY POINT TEMP/POPS
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 088 066/092 068/090 067/102 070/102 070/099 068/097
2/B 20/U 54/W 01/G 21/G 21/U 21/U
LVM 086 057/090 058/090 058/098 061/098 061/097 059/095
2/T 25/T 75/T 11/U 12/T 22/T 22/T
HDN 090 064/094 066/090 063/102 066/103 068/101 066/099
2/U 20/B 45/T 00/G 11/G 21/G 21/U
MLS 085 064/092 067/092 066/104 071/104 073/103 070/101
2/W 20/U 11/B 10/G 10/G 21/G 11/G
4BQ 088 065/091 066/087 064/101 070/102 071/100 069/099
2/U 41/B 56/T 10/G 11/G 21/U 21/U
BHK 082 059/089 060/090 061/101 067/104 068/102 065/100
2/W 10/B 01/B 10/G 11/G 21/G 11/U
SHR 091 061/090 062/085 059/097 064/098 065/096 063/094
2/U 34/T 78/T 11/U 02/T 12/T 22/T
BYZ WATCHES/WARNINGS/ADVISORIES
MT...FLOOD WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR ZONES 56-64>67-138-139-169>171.
WY...FLOOD WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH LATE
WEDNESDAY NIGHT FOR ZONES 198-199.
WEATHER.GOV/BILLINGS
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page